Collision avoidance system for vehicles using digital logic circuitry and retro-fitting techniques

ABSTRACT

A continuous exterior perimeter monitoring system for collision avoidance by vehicles with exterior objects is provided utilizing microelectronic digital logic circuits and techniques to produce a visual three-digit numerical display, a discrete multi-color display and a multi-level sound warning system, indicating precise and range of distances of exterior objects from vehicles which could collide therewith within pre-selected distances. The time-to-distance circuits of the system are an integral part of the digital logic circuits that are utilized to ascertain distances and such circuits are in a compact electronic package adapted to and is readily installed and integrated into existing vehicles utilizing the existing wiring electrical power systems primarily as a retro-fitting process for vehicles or as an original installation.

This application is a continuation-in-part of application Ser. No.08/000,487, filed Jan. 5, 1993, entitled "COLLISON AVOIDANCE SYSTEM FORVEHICLES USING DIGITAL LOGIC CIRCUITRY AND TECHNIQUES", now abandoned.

FIELD OF THE INVENTION

The present invention relates to collision avoidance systems forvehicles and the retro-fitting of such vehicles utilizing the existingelectrical wiring systems thereof. Such vehicles are usually pre-wiredduring manufacture with wiring harnesses that are used to operate andmonitor such vehicle functions as, side and back marker lights, licenceplate lamps, turn signal and hazard lamps, stop lamps, back-up lightsand anti-lock brake devices and the like. Prior art electrical systemsfor vehicles such as tractor-trailers traditionally provide access tothese electrical functions through what is commonly called an electrical"nose-box", which may be more specifically defined as a multicable orharness interconnection female-male plug device having femalereceptacles for receiving a multi-cable male interconnect adaptor devicehaving prongs corresponding to the female receptacles. In general, thevarious wire conductors of such arrangements are used as the power andreturn lines for an electrical function of the vehicle. The presentinvention utilizes this wiring arrangement to advantage in gainingaccess to the power system and other wire conductors for communicatingdigital logic signals from place to place in a vehiclar arrangement oftractor-trailers and otherwise.

BACKGROUND OF THE INVENTION

In the prior art to which this invention relates, there have beenprovided ultrasonic devices attached to the rear of vehicles, such astrucks to measure the distance between the rear end, tail-gate or otherportions of the vehicle and a loading platform as an example. Othervehicles have been provided with ultra-sonic listening devices forwarning when the noise level of an exterior object reaches a levelindicative of collision possibilities. Some of the prior art systems usea plurality of transducers located around the sides of the vehicle andare connected to transmitters for sending sonic or electromagneticpulses to distant objects. Each transmitter is correlated with areceiver for detecting sonic or electromagnetic reflected echoes fromobjects close by. The output of each receiver may be connected toindividual indicator lamps and/or a warning device such that if any ofthe lamps is energized, the driver is warned that one or the other sideof the vehicle is in danger of a possible collision. Other prior artdevices in this art utilize mechanical means for switching thetransmitter and receiver on and off, during the transmit or receivecycles, while yet other devices utilize radar systems or use a signalbeacon type system for detection of objects. However, none of the priorart systems known to applicant utilize microelectronic digital logiccircuitry and techniques to transmit and acquire returned echo signalsconverted to voltage signals to effectuate the measurement oftime-to-distances of objects at discrete distances or within discretedistance ranges for display by processing such voltage signals withdigital logic circuits and techniques to provide three forms of warningaids simultanously from the same echoed signals with a high degree ofaccuracy.

Reference to the following prior art patents will indicate the generalstate of the art as they may relate to the present invention asexamples:

U.S. Pat. No. 3,842,397, to Thomas Sindle, issued Oct. 15, 1974; U.S.Pat. No. 3,975,708, to Joe F. Lusk, issued Aug. 17, 1976; U.S. Pat. No.3,944,981, to Shigeyuki Akita, issued Mar. 16, 1976; U.S. Pat. No.4,015,232, to Thomas Sindle, issued Mar. 29, 1977; U.S. Pat. No.4,278,962, to Pin-Houn Lin, issued Jul. 14, 1981; U.S. Pat. No.4,349,823, to Katsutoshi Tagami, issued Sep. 14, 1982; and U.S. Pat. No.4,626,849, to John C. Sims, issued Dec. 2, 1986.

SUMMARY OF THE INVENTION

With a view toward utilizing the electrical wiring and power systems ofexisting vehicles to advantage, the present invention may becharacterized as a "retro-fit" to existing vehicles, particularly withrespect to large truck tractor-trailer arrangements, including tandenarrangements, so as to provide access to the existing electrical wiringsystem, thereby avoiding the disruption thereof or the need to provideindependent electrical wiring systems to effectuate a retro-fit andintegration of the present invention with existing electrical wiring andpower systems. This is especially desireable and economicallyadvantageous when a new system in accordance with the present inventionis to be integrated into a fleet of existing tractor-trailers by aretro-fit.

The present invention provides the unique advantage of an electricalwiring system that may be adapted to the traditional wiring systemutilizing low power voltage to drive microelectronic digital logiccircuitry powered by the vehicle's existing battery system. Morespecifically, microelectronic digital logic circuits of the presentinvention uses high frequency acoustical waves transmitted and receivedreturned echo signals to develop time-to-distance ranging signals ofremote exterior objects that are processed and converted intopreselected incremental and exact distances from the vehicle's exteriorperimeter to thereby provide continuous monitoring for collisionavoidance. Such distances are presented as warnings as a three digitnumerical display, multi-distance discrete color display and audiowarnings so as to avoid collisions with exterior objects in closeproximity thereto. The three digit numerical display is generated by useof digital logic circuitry having time-to-distance conversion circuitswhich in combination with digital binary counter circuits therein,generate the numerical display. While the multi-color display ofdistances to objects and the audio warning alarms are generated by meansof digital logic circuitry having at least three voltage comparatorcircuits for generating the logic signals required to actuate the colordisplay and audio warning alarms.

Therefore, it is an object of the present invention to provide acollision avoidance system that may be readily adapted to andinterchangeable within existing electrical systems for largetractor-trailers by means of a retro-fit.

Another object of the invention is to provide a multi-color visual paneldisplay indicating at least three discrete distance ranges and two ormore levels of audio alarm devices both located in the compartment of avehicle as a continuous warning aid to the vehicle operator.

Yet another object of the invention is the provision of a uniquemicroelectronic digital logic circuit system for generating ongoingtime-to-distance parameters from transmit and received echo signals fromexterior bodies that may cause collision incidents which are convertedinto priority encoded signals representing at least three discretedistances within a preselected range of distances for continuous displaythereof and at least two discrete distances within a range of distancesfor audio warnings and utilizing such signals to generate correspondingthree digit numerical displays as an aid to verification of suchdistances.

While another object of the invention is the provision ofmicroelectronic logic circuitry that is readily adaptable to andcompatable with existing and/or future vehicles systems to accomplishthe recited and other objects heretofore unrealized in the prior artsystems.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are believed to be characteristic of theinvention as to its organization, method of construction and operation,will be better understood from the following description considered inconnection with the accompanying drawings, in which illustrativeembodiments of the invention as disclosed by way of examples.

In the drawings:

FIG. 1 is a plan view of a truck tractor-trailer vehicle arrangementdepicting the type of vehicles that may utilize the present invention toadvantage for collision avoidance;

FIG. 2 is a rear view of the trailer shown in FIG. 1, that illustratesthe location of several acoustical transducer/receiver devices disposedat exterior surfaces thereof;

FIG. 3 is a front view of the tractor shown in FIG. 1, that alsoillustrates possible locations of acoustical transducer/receiver devicesdisposed thereon;

FIG. 4 depicts a block diagram of a microprocessing and warning systemwhich utilizes the electrical wiring and battery system of the vehiclararrangement and the several microelectronic digital logic circuitcomponents and their interconnections to communicate digital logicsignals from a trailer to an operator's compartment of a tractor;

FIG. 5 depicts an electrical nose-box wiring connection adaptor shown inFIG. 1 in the broken line circle, illustrating a receptacle with suchmultiple wiring connections as ground, signal and auxiliary componentsand the like;

FIG. 6 depicts several block diagram circuits and a visual display panelof a warning system disposed in the operator tractor compartment, whichillustrates a plurality of discrete color and numerical indicators in agroup representing the possible locations of acousticaltransducer/receiver devices shown in FIGS. 1, 2, and 3;

FIG. 7 is a block diagram of a numerical display and a processingcircuit shown in FIG. 4, illustrating its interface with other circuitsof the system;

FIG. 8 is a block diagram of a voltage comparator processing circuit andwarning system including a multicolor display and audio generatingcircuit shown in FIG. 4, illustrating their relative inter action andinterface with other circuits of the system;

FIG. 9 depicts a view of a trailer marker light, partly in cross-sectionthat is adapted to house a transducer/receiver device therein, that isdisposed at various perimeter locations of the trailer or tractor shownin FIGS. 1,2 and 3;

FIG. 10 depicts a plot of the acoustical wave beam pattern transmittedby the transmitter device shown in FIG. 9;

FIG. 11 depicts a plot of the transmitted response oftransmitter/receiver device shown in FIG. 9, and denotes the frequencyresponse band selected for use in accordance with the present invention;and

FIG. 12 depicts a plan view of a tractor-trailer, having a tandemtrailer arrangement, illustrating the use thereof according to thepresent invention.

It it is understood that the phrases transducer/receiver andtransmitter/receiver are the same and may be used interchangeably in thecase.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings FIGS. 1 through 12, the invention will bedescribed with reference to the illustrative embodiments of the presentinvention. In FIG. 1, there is shown a motor vehicle 10 having acommerical truck tractor 12 with a driver/operator compartment 14 and atruck battery 16 to supply direct current voltage as part of theexisting electrical power system. Connected to tractor 14 is aconventional cargo trailer 18 which may have a length in excess of 20feet. As shown in FIG. 1, there is depicted the possible locations for aplurality of clearance/marker light devices 20, which is also thelocations of a plurality ultra-sonic acoustical transducer/receiverdevices 22 in accordance with the teachings of the present invention. Insome reto-fit applications the clearance/marker light devices may beadapted to be occupied by transducer/receiver 22 along with the markerlight. A plurality of broken lines 24 at the rear of trailer 18 areshown to illustrate the propagation coverage from transducer/receivers.It should be noted that the wave sound coverage fromtransducer/receivers 22 may be rather complete with respect to areas ofconcern. FIGS. 2 and 3 depict the rear and front tract-or-trailerarrangement, respectively, illustrating the possible locations oftransducer/receiver devices 22.

Referring now to FIG. 4, there is shown an illustrative block diagramdepicting the various circuit components of the system of the invention.More specifically, vehicle compartment 14 is shown as containing acollision avoidance warning system 26, including visual displays of anumerical display 88 and a multi-color display 42; and an audio warningdevice 28 which may be one or more units that are capable of producingat least two levels of audio sound or audio messages. In FIG. 1, thereis shown a nose-box adaptor 30 disposed at the rear of tractor 12,identified as (NB), in broken line circle. The details of the nose-boxare shown in FIG. 5, illustrating the wiring conductors available fromthe various receptale connections of the vehicles such as a tractortrailer arrangement, including a ground connection and other conductorsand an auxiliary or unused receptacle 32 that may be used for access tothe electrical wiring system of the vehicles in accordance with thepresent invention.

Returning to FIG. 4, battery 16 is grounded by connection 17 to thechassis of the vehicle, and the battery is shown connected to an inputan oscillator circuit 34. A positive voltage input line 32 is connectedto circuit 34 which operates as the positive voltage source for theentire distance monitoring and measuring system. The system of thisinvention utilizes positive 5 volts throughouas the voltage referencelevel. The other circuit components include a distance ranging circuit46, that is connected to circuit 34 by a first input line 48 forreceiving a voltage oscillatory signal. Distance ranging circuit 46 isconnected by a first output line 50 to a transducer/receiver 22 forinputting a low frequency high voltage clock signal thereto, and isconnected by a second output line 52 to transducer/receiver device 22for inputting a high frequency low voltage trigger and reference signalthereto. A second input of distance ranging circuit is connected todevice 22 for receiving returned echo analog signals 54 therefrom.

Continuing with FIG. 4, oscillator circuit 34 is connected at secondoutput terminal 36 for outputting system voltage power to distanceranging circuit 46, device 22, a digital logic processing circuit 38,and a voltage comparator processing circuit 40; a third output terminal37 is connected for outputting anan oscillatory signal to digital logiccircuit 38 and voltage comparator processing circuit 40. All of theforegoing circuits, namely oscillator 24, distance ranging circuit 46,device 22, digital logic processing 38 and voltage comparator processing40 are grounded to the chassis of the vehicle. When distance rangingcircuit 46 receives returned echo analog signals 54 from device 22, theyare converted to digital logic signals that are outputted along with ahigh frequency low voltage signal, referred hereinafter as "two outputsignals" 53 and 55. It is noted that output signal 53 is the same signalinputted to device 22 along output line 52 as a trigger and referencesignal. There is a time-to-distance relationship between signals 53 and55, as they emerge from distance ranging circuit 46 in the form ofdigital logic signals which is a measure of the distance between avehicle and an exterior object.

To continue it can be seen that the two output signals 53 and 55 are fedas inputs to digital logic processor 38 and voltage comparator processor40. The output signals generated by processor 38 are voltage biasingsignals 87 and binary-to-seven segment conversion signals 95 that arefed to a digital numerical display device 88 through a series connecteddiode 200 and a conductor 202 that is in turn connected to conductor 32.A conductor 206 is connected to conductor 32 through an interfacecircuit 204 which carries digital logic signals from circuit 38 an 40 towarning devices 88, 42 and 28 so as to produce the appropriate displaysand audio warning sounds or messages of warning device 26.

As shown in FIG. 4, devices 88, 42 and 28 are all electrically groundedto the chassis of the vehicle through a conductor 208, and each receiveselectrical power through a conductor 210 to which they are connected andwhich in turn is connected to conductor 32 through a series connectedvoltage device 212. Also shown in FIG. 1, is a conductor 214, shown as abroken line, as an alternate conductor connection between amicroprocessor 89 and warning system 26, including devices 88,42 and 28,that is connected directly to conductor 206. Conductor 214 may becharacterized as an unused conductor contained in the pre-existingwiring arrangement of the vehicle arrangement, such as atractor-trailer, illustrated and discussed with respect to FIGS. 1 and5. It should be noted in FIG. 4, that a marker light 20 is shown ascontaining device 22 therein by the notation of a broken-line 220, whilean exterior object 19 is shown receiving transmitted incident soundwaves and also reflecting returned echo sound waves.

Referring now to FIG. 6, there is shown an illustrative warning displaysystem 26 which has been depicted as being located in thedriver/operator compartment 14 of truck-tractor 12. As shown each of thedesignated locations thereon is depicted by three squares havingcharacters G for green, Y for yellow and R for red. Each of thesesquares represents an array of light-emitting-diodes(LED), that maybecome illuminated indicating distance ranges between the surfaces ofthe vehicles and a remote exterior object.

More specifically, when square G is illuminated it indicates that theobject is between 10 to 15 feet from the surface of the vehicle in anarea where an acoustical transducer/receiver 22 is disposed, square Yindicates a distance range of 5 to 10 feet and R is 0 to 5 feet. Itshould be noted that these distance ranges are related to the threedigital logic voltage comparator circuits of a microprocessor 89, thatmay be preset to voltage levels which generate appropriate outputsignals corresponding to such distance ranges whenever proper ANDsignals are received by such preset voltage comparators. In FIG. 6 thereis also shown a priority encoder circuit 58 depicting the circuit whichinterfaces with the array of LED that are the light sources for eachgreen, yellow and red squares of the display panel 42 of warning system26. A pair of audible alarm circuits and devices 60 and 62, are shownconnected to outputs from priority encoder 58, so as to generate themultilevel warning signals associated with distances between 0 to tenfeet as depicted. It should be noted that the distance ranges may beadjusted to be actuated in different distance ranges, if desired.

It is to be further noted that the circuit components connected anddisposed at location A along with the numerical digital displays ofdisplay 88, denoted by an encircled N, are similarly connected tolocations B through H and operate in the same manner as discussed withrespect to location A. The appropriate circuits in each case B through Hhave been omitted in the interest of brevity in the discussion thereof.

Referring now to FIG. 7, there is shown a block diagram in more detailof the essential circuit components of the system wherein digitaldisplay circuit 38 is for receiving a plurality transmitter trigger andreference output signals 53, that are the same as signals fed toconductor 54, and a plurality of digital logic echo output signals 55from distance ranging circuit 46 that are to be processed by digitallogic circuit 38. Transducer trigger and reference output signal 53 areinputed to a logic reference latch circuit 64 so as to set the circuitin a state of readiness for the commencement of a cycle oftime-to-distance determinations of detected remote objects and echooutput signals 55 are inputed to a logic latch circuit 66 as a setsignal which causes the time-to=distance process to begin. A resetsignal from circuit 64 is inputed to circuit 66 to put it in a state ofreadiness for receiving echo set signals 55 once an echo activationpulse signal is acquired and transmitted to circuit 66; at the sameinstant a second reset signal 68 from circuit 64 is inputed to atime-to-distance conversion circuit 70, and a third reset signal 72 isinputed to a three-digit binary counter circuit 74, to put circuits 70and 74 in a state of readiness. These reset signals are reoccurringduring the start of each cycle of time-to-distance determination. Asshown in FIG. 7, a system clock 96, is the oscillator circuit 34depicted in FIG. 4.

Conversion circuit 70, receives clock pulses from a high frequency clocksource 76 that is on the order of 420 kilohertz (kHz) and such highfrequency is chosen to provide a high degree of accuracy required forthe system. Circuit 70 processes the clock input from circuit 76 toproduce two output signals, a clock reference pulse input signal 78characterized as 178 micro-second pulses per cycle and a scanning clockpulse signal 80 characterized as 4.6 microsecond pulses per cycle, whichare both inputed to the three digit binary counter circuit 74. Binarycounter circuit 74 outputs a reset signal 82 to reference latch circuit64 clearing the circuit at the end of each cycle so that the next cyclecan commence. The time-to-distance process is commenced bu an latchenable signal 81 from echo latch 66 to binary counter circuit 74 througha coupling circuit 83.

The time-to-distance calculations for objects remote to the surface ofthe vehicle where the plurality of transducer/receiver devices 22 aredisposed, is inversely proportional to the transmission frequency ofdevices 22 and may be better understood by reference to the followingformula:

    λ=c/f

where λ is the wavelength measured in feet per cycle

c--is a constant, the speed of sound at approximately 1,100 feet persecond and

f--is the frequency at which the transducers transmit in cycles persecond.

Thus it can be seen that one foot of distance travelled in air is about0.99 milliseconds and five feet is approximately 4.6 milliseconds. A 4.6microsecond per cycle scanning clock selected for the illustrativeembodiment in the disclosure relates to the distance range of 5, 10 and15 feet, correspond to red, yellow and green color displays shown on thedisplay panel of warning system 26, in that it is 1/1,000 of the timerequired to scan 5 feet of distance in air.

Continuing with the description of FIG. 7, the output signals of countercircuit 74 are from scanning clock input 80 in cooperation with clockreference input signals 78, are a plurality of diode biasing outputvoltages 84, generally designated D₁, D₂, and D₃, that are inputed to afirst drive circuit 86 which in turn are inputed as signals 87 to a setof three light emitting diodes as part of a 3-digit numerical display88. These inputed bias voltages 87 are used for biasing and determiningwhich and when each diode will be turned on during each cycle of adistance determining event. A second set of output voltage signals 90from counter circuit 74, are characterized as binary-code-decimalvoltages, generally designated as 90 and are inputed to abinary-to-seven segment conversion digital logic circuit 92. Conversioncircuit 92 includes a digital logic matrix which utilizes thebinarycoded decimal voltage signal to activate various combinations oflight-emitting-diodes. The seven segments of each 3-digit display isactivated by inputing a signal to the light-emitting-diodes which arebiased for emission when a second signal 95 from a drive circuit 94 isapplied. The output signals of circuit 92 inputed to drive circuit 94 soas to activate the applicable segments of each of the digital displays.Various segments of the seven segment display are excited when an outputlogical low signal is generated by circuit 92. When signals 90 areapplied as discussed, the three digits display numerical characterscorresponding to the distance of a detected object is produced withrespect to the surface of a vehicle utilizing the system in accordancewith the present invention. The resulting three digit numericalcharacter display 88 is useful as a direct reading of distance and as averification of red, yellow and green displays shown on the displaypanel of collision avoidance warning system 26, located indriver/operator compartment 14 of tractor 12, and as a precisemeasurement of distance.

Referring now to FIG. 8, the description of the system is continued witha discussion of the voltage comparator processing circuit 40 forgenerating digital logic signals for multicolor display 42 and audiowarning devices 28. As shown in FIG. 8, circuit 40 is essentially ablock diagram for ease of description as to the organization andoperation. An oscillation and a NAND digital logic circuit 96 isprovided which commences its operation by the generation of anoscillation signal input to a drive and logic circuit 98. An oscillationsignal 100 is inputed from circuit 98 to a voltage switching interfacecircuit 102, which has a transistor Q₃ that switches on and off,responsive to oscillation signal input 100, to generate voltageswitching pulse signals generally designated VSW. Oscillation signal 100is chosen at 5 cycles per second and causes VSW interface circuit 102 togenerate an output signal to input line 48, which is connected todistance ranging circuit 46. The circuit 102 functions as circuit 34shown in FIG. 4. The VSW signal is characterized as a 50 kilohertzsignal having a cycle on the order of 20 microseconds wide with anamplitude of at least plus 5 volts, which corresponds to the clockreference voltage signal of the system fed to device 22 along outputline 50 of circuit 46. The distance ranging circuit 46 generates apositive high voltage output signal fed along conductor 52 which is onthe order of plus 300 volts as a trigger and reference signal causing agroup of 56 pulses per cycle output signal from transducer/receiver 22during a one millisecond on-time of a cycle. The interval between thegroup of 56 pulses is characterized as the off-time, during which timedevice 22 operates as a receiver of returned echo sound waves. Duringthis off-time the receiver section operates so as to receive 5 echoedpulses prior to sending a true echo signal pulse 54 back to distanceranging circuit 46. The receipt of a series of 5 echoed pulsesestablishes a priority acquisition event of the system as to which echopulses are used to determine the distance of a detected objected. Stateddifferently, objects nearest to the vehicle will produce a series of 5pulses before a more remote object provides an appropriate set of 5pulses. Thus, this feature of the invention uniquely operates to discernthe closest objects from the more remote ones. This unique featureeliminates more complex systems which would be required to distinguishbetween multiple distance echoes. It can readily be understood that itis most desireable to identify close-in objects at the earliestopportunity, since the closer objects are those that which would cause apossible collision with the vehicle as compared with those objects thatare not as close to the vehicle. The receipt of the 5 returned echoedpulses establishes a true pulse and has a relevant relationship to thethe 178 microsecond per cycle clock signal in binary counter 74 ofcircuit 38. More specifically, by dividing 178 microseconds per cycle by35.6 microseconds per pulse, 5 pulses per cycle is derived. Anotheraspect of the system is to note that the 4.6 microsecond per cyclescanning clock is small enough, on the order of 1,000 scans per 5 feetof distance travel of the transmitted signal to provide a high degree ofaccuracy desired in the detection of echoed pulses, that are used toproduce the output signals from binary counter 74 which are utilized togenerate the numerical characters for discussed hereinabove with respectto FIG. 7.

Returning now to FIG. 8, it can readily be see that reference triggeringsignal 53 and echo signals 55 are outputed from distance ranging circuit46 and inputed to drive circuit 98 of circuit 40. These two receivedsignals, 53 and 55, are processed and inputputed to oscillator/NANDcircuit 96 and a dual flip-flop circuit 110, respectively. Processing ofsignals 53 and 55 between interacting digital logic circuits 98, 96 and110 produces two output signals 112 and 114 from the drive circuit 98.When an output signal 116 is low and inputed to drive circuit 98, outputsignal 112 is generated and when an output signal 118 is high andinputed to drive circuit 98, output signal 114 is generated.

Output signal 112 is inputed to three voltage comparators a firstvoltage comparator 120, that operates as a dual voltage comparatorcircuit, and a second voltage comparator 122 that operates as a voltagecomparator and a regulator. Output signal 114 passes through a resistorR₁₆ which is coupled with an output signal from two series connecteddiodes, designated 124, to input a non-inverted pulse voltage tocombination comparator circuit 122. Another portion of output signal 112passes through a resistor R₁₄ which is inputed to a collector of atransistor 126 and another signal is inputed to the base of transistor126 from circuit 122. These circuit signals to transistor 126 causes anoutput signal from the collector of transistor 126 that is inputed tocircuits 122, and both segments of voltage comparator 120.

Each of the three voltage comparators, i.e. dual comparators of circuit120 and comparator 122 are set at three discrete low voltage levels of0.7, 1.4 and 2.1 volts, respectively, wherein an output low signal is inthe range of 0 to 2.5 volts, may be outputed representing a binary lowoutput signal as a binary zero. When the comparators receive a highsignal in the range of 2.6 to 5.0 volts, no output signal is created,resulting in a binary one. Stated differently, the comparators producean AND output when the respective comparators receive input voltagesthat are equal to the preset voltage levels thereof and is a low signalwhen a zero occurs. When no voltage match occurs in a comparator theoutput is a high and a one occurs.

As shown in FIG. 8, a priority encoder 58, has two inputs from dualvoltage comparator 120 and one from comparator circuit 122. These threeincoming signals are processed by encoder 58 which in turn become inputsto a visual display 42, that includes an array of light-emitting diodes(LED). When these encoded signals are applied to the LEDs, theydetermine which of the LEDs will be energized to produce a display ofred, yellow or green, designated R, Y and G, respectively, asappropriate which correspond to the distances of detected objects remotefrom a surface of the vehicle. It should be recalled that the colors,i.e. red, yellow and green represent a range of distances 0-5, 5-10 and10-15 feet, respectively. The same signals inputed to encoder 58, arealso utilized to activate an audio sound warning device 44, such asmultiple sound buzzers or sound message devices included in device 44.

Referring to FIG. 9, a marker light device 20 is depicted partly incross-section. As shown marker light 20 has a mounting plate 130 thatextends the length of the device and includes threaded mounting holes132 for receiving screws or bolts for mounting the marker lights to thevehicle. Attached to mounting plate 130 is an enclosure 134 including alight transparent marker lens 136. On the right side of center line 138,is another marker lens 136 that has been adapted to receive and containcoustical device 22 along with an o-ring 140 for sealing device 22 fromclimatical conditions. Also shown is a negative electrical terminal 142for electrical grounding thereof and a positive terminal 144 forreceiving electrical input signals and for outputting signals. Terminal144 is used for both incoming and outgoing signals. Outgoing acousticalwaves a indicated by arrows 146 while returned echo waves are indicatedby arrows 148.

Referring to FIG. 10, there is shown a typical beam or transmittedacoustical wave pattern 150 of device 22, when activated by a triggersignal at 50 kilohertz frequency. FIG. 11 shows a transmit frequencyresponse curve 152, illustrating that the energy output response isrelatively uniform in the frequency range of 50 to 60 kilohertz (kHz) asshown in the area of the curve between broken lines A-B of FIG. 11.

Continuing with reference to FIG. 12, there is depicted atractor-trailer arrangement with two trailers 18 and 18', connected intandum to tractor 12, similar to the single tractor-trailer arrangementof FIG. 1. As shown in FIG. 12, these vehicles are interconnectedelectrically by a traditional wiring harness 21 and 21' compatable withnose-box adaptors 30. The wires of harness 21 and 21' are compatablewith the pre-wired systems of prior art trailers 18 and 18'.

It should be noted that devices 22 are disposed at each of eightlocations A through H, corresponding to marker lights 20 locations, showin FIG. 6 and all units a energized from distance ranging circuit 46. Inpractice, a maximum of eight transducer/receiver devices should beactivated by a single distance ranging circuit 46 for most efficientoperation. If additional devices 22 are desired per vehicle, anadditional distance ranging circuit 46 shoud be used. It should beunderstood that digital logic processing circuit 38 and voltagecomparator processing circuit 40 are both capable of accommodatingsignal input from at least twenty-four devices 22 for efficientoperation.

Another embodiment of the invention encompasses the use of suitablelogic circuitry and techniques that enable a plurality oftransducer/receiver devices 22 to used in asymmetrical or sequentialmode of operation rather than having all of devices 22 activated atonce. This embodiment recognizes that the order of priority in theacquisition of echo wave signals to establish or lock-in on a specificdetected object is predicated on the nearness of the object in a ratherlimited area surraounding the surface of the vehicle and the need toreceive five consecutive object echoed pulses. A clear understanding ofthe invention reveals that it is intended primarily for detectingstationary or slowly moving objects in near proximity to the spacesurrounding the vehiclar arrangement. For example, it may be desireable,when a tractor-trailer vehicle is backing into a loading dock, to havethe rearward looking transducer/receiver devices 22 continuouslyactivated while the side and front mounted devices 22 are activated in apreselected mode of operation, but not continuously. Various preselectedmodes of operation may be readily implemented by modifying distanceranging circuit 46 with a switching device located in the operatorcompartment 14 so that the operator can make the appropriate selectionfor the mode of operation desired. Such modifications of operation canreadily be accomplished by modifications of the digital logic circuitryof distance ranging circuit 46 in conjunction with any switchingarrangements provided in operator compartment 14.

At this juncture it may be note worthy to observe and emphasize certainunique features of the invention, namely:

a. the use of a traditional vehicle battery as the existing electricalpower souce along with the vehicle's existing wiring system and nose-boxadaptors for tractor-trailer arrangements providing a quick and easymeans for retro-fitting existing truck tractor-trailer fleets;

b. use of digital logic processing circuitry and accompanying low powerconsumption therefor for high efficiency and economical operation;

c. the use of multiple pulse wave acquisition of echoed signals fromexterior objects closest to the vehicle or sections thereof of mostconcern and to increase the accuracy of acquisition of echoed signals bymeans of the five consecutive pulse technique in accordance with thedisclosure of the present invention, to establish a true echo as thesignificant returned echo for processing;

d. use of the digital clock scanning technique in connection with thefive pulse echo acquisition technique for accuracy of thetime-to-distance determinations that is readily converted to numericalread-out from binary coded decimal data generated from such clockscanning process; and

e. the ability of the system of the invention to provide warnings inthree different modes of presentation.

The foregoing and other advanges of the present invention are clearlyapparent and recognizeable from the disclosure and offers advantagesheretofore believed to be unavailable in the prior art.

The foregoing disclosure, drawings and teachings of the presentinvention readily and adequately demonstrate that identifying thespecific distances and areas of locations of exterior objects remotefrom a vehicle or a vehiclar arrangement by means of received acousticalwave echo sinals from objects can be used to great advantage forconverting such signals to digital logical signals for processing andinterpretation by means of microelectronic digital circuitry. The use ofthese techniques provides aids to the driver/operator in the form ofnumerical, multicolor and audio warning presentations.

It is to be clearly understood that the above described embodiments areonly illustrative of the principles applicable to the invention. Variousother arrangements or modifications may be defined by those skilled inthe art without departing from the spirit and scope of the invention.Consequently, it is understood that the present invention is intended tocover such modifications and the invention is limited only by the spiritand scope of the descriptive disclosure, content of the drawings and theappended claims.

What is claimed as new is:
 1. A microelectronics collision avoidancedetection and warning system having a plurality of detection devicesremotely disposed about a perimeter of a vehicular arrangement fordetermining a distance between exterior objects and said vehiculararrangement by installing it as a retro-fit to the vehicular arrangementutilizing existing electrical wiring and power system thereof includingits chassis, said installed retro-fit provides warnings to an operatorcompartment of the vehicular arrangement from said detection devices inthe form of visual numerical and multicolor displays, and multiple audiosounds and messages, the combination comprising;a. a digitalmicroprocessor having an oscillator circuit with an input connected tosaid existing electrical wiring and power system of a vehicle for inputof electrical power, and including a plurality of output terminals, saidoscillator circuit generating oscillatory frequency output signals forsaid detection and warning system and electrically grounding through thechassis of said vehicle; b. a distance ranging circuit connected at afirst input terminal of an output of said oscillator circuit forreceiving an oscillatory frequency signal and generating a low frequencyhigh voltage clock output signal and a plurality of high frequencytrigger and timing reference output signals; said distance rangingcircuit having a second input terminal for receiving a plurality ofanalog echo return signals that are converted by said distance rangingcircuit into a plurality of digital logic echo output signals; saidplurality of high frequency trigger and timing reference output signalsand digital logic echo signals being represented as two output signalshaving a time-to-distance relationship therebetween from which thedistances between said vehicle and a plurality of exterior objects canbe measured; c. said plurality of detection devices include adual-function acoustical detection device each operates first as atransmitter and subsequently as a receiver of ultrasonic acousticalsound waves and are disposed at selected perimeter locations of saidvehicle; each of said acoustical detection devices has an input terminalconnected to said distance ranging circuit for receiving said lowfrequency high voltage clock and said high frequency trigger and timingreference output signals therefrom to activate said acoustical detectiondevices as transmitters of a plurality of incident sound waves andsubsequently as receivers of a plurality of returned echo sound waves;said plurality of returned echo sound waves being fed from saidacoustical detection devices through said input terminal as analog echoreturn output signals to said second input terminal of said distanceranging circuit; a second terminal of said acoustical detection devicesbeing connected to the vehicle chassis for electrical grounding; d. adigital logical processing circuit having a first input terminalconnected to said oscillator circuit for receiving an oscillatoryfrequency output signal; a second and third input terminal connected tosaid distance ranging circuit for receiving said two output signalshaving a time-to-distance relationship therebetween and converting saidtwo output signals into a plurality of voltage biasing signals andbinary coded decimal-to-seven segment digital logic signals that are fedto said existing electrical wiring and power system through a seriesconnected diode device; e. a voltage comparator processor circuit havinga first input terminal connected to said oscillator circuit forreceiving an oscillatory frequency output signal; a second and thirdinput terminal connected to said distance ranging circuit for receivingsaid two output signals having a time-to-distance relationshiptherebetween and for converting said two output signals into a pluralityof voltage signals that includes three ranges of voltages determined bypreset voltage comparator circuits; each of said three ranges ofvoltages has a plurality voltage response levels which represent atime-to-distance measurement between said vehicle and an exteriorobject; said three ranges of voltage signals are fed to said existingwiring and power system through a series connected diode device; f. anelectronic digital logic signal warning apparatus remotely disposed fromsaid detection devices, including a plurality of audio sound devices incombination having an output terminal and a plurality of inputterminals; a first input terminal being connected to said existingelectrical wiring and power system through a voltage divider circuit forinput power and said output terminal being connected to said chassis forelectrical grounding; and said other input terminals being connected tosaid existing electrical wiring and power system through a seriesconnected interface circuit for receiving digital logic signals andactivating said plurality of audio sound devices to generate multiplewarning sounds and messages; g. a numerical visual display systemincluding a plurality of light emitting diodes in combination having anoutput and a plurality of input terminals; a first input terminal beingconnected to said existing electrical wiring and power system throughsaid voltage divider circuit for electrical power and said outputterminal being connected to said chassis for electrical grounding; saidother input terminals being connected to said existing electrical wiringand power system through said series connected interface circuit forreceiving digital logic signals for activating said plurality of lightemitting diodes to produce a display of numerical characters of threedigit-seven segment configuration; and h. a multicolor display includingan array of light-emitting-diodes in combination having an output and aplurality of input terminals, a first input terminal being connected tosaid existing electrical wiring and power system through said voltagedivider circuit for electrical power and said output terminal beingconnected to said chassis for electrical grounding; said other inputterminals being connected to said existing electrical wiring and powersystem through said series connected interface circuit for receivingdigital logic signals and for activating said array oflight-emitting-diodes to produce a display of multiple colored squareareas, wherein each said square areas represents a distinct range ofdistances measured between said vehicle and exterior objects asdetermined by said three ranges of voltage signals of said voltagecomparator processor.
 2. A microelectronics collision avoidancedetection and warning system of claim 1, in which said digitalmicroprocessor derives its electrical power from a positive currentcarrying wire of said existing electrical wiring and power system.
 3. Amicroelectronics collision avoidance detection and warning system ofclaim 1, in which said output of said digital microprocessor and saidinputs of said warning system receive digital logic signals directlyfrom an auxiliary wire of said electrical wiring and power systemwithout any connected interfacing devices.
 4. A microelectronicscollision avoidance detection and warning system of claim 1, in whichsaid trigger and reference signals are further defined as a group of 56pulses during an on-time cycle.
 5. A microelectronics collisionavoidance detection and warning system of claim 1, in which said digitalmicroprocessor includes a plurality of said distance ranging circuits.6. A microelectronics collision avoidance detection and warning systemof claim 1, in which said voltage comparators are preset to respond tovoltage ranges corresponding to measured distances of 0 to 5, 5 to 10and 10 to 15 feet.
 7. A microelectronics collision avoidance detectionand warning system of claim 1, wherein said electronic microprocessor isconnected directly to an auxiliary wire of said existing electricalwiring and power system without the benefit of an interfacing device. 8.A microelectronics collision avoidance detection and warning system ofclaim 1, wherein each of said acoustical transducer/receiver devices aredisposed and contained within an individual marker light of saidvehicular arrangement.
 9. A microelectronics collision avoidancedetection and warning system of claim 1, wherein said digitalmicroprocessor and said collision avoidance and detection warning systemderives electrical power from a positive current carrying wire of saidexisting electrical wiring and power system.
 10. A method ofretro-fitting multi-member vehicles with an electronic microprocessordigital logic detection and warning system for collision avoidance withexterior objects, utilizing an existing electrical wiring and powersystem common to the vehicles, comprising the following steps:a.connecting a retro-fit circuit assembly including an electronicmicroprocessor, having circuit components consisting of a plurality ofacoustical transducer/receiver devices, an oscillator, a distanceranging circuit, a voltage comparator and digital logic processingcircuits, to the existing electrical wiring and power system of saidvehicles for receiving electrical power therefrom; and connecting anoutput of said electronic microprocessor to a vehicle chassis forelectrical grounding; said acoustical transducer/receiver devices beingdisposed at selected exterior perimeter locations of said vehicles; b.connecting said electronic microprocessor to said existing systemthrough a series connected diode to provide one-way digital logicsignals flow from said electronic microprocessor to said existingelectrical wiring and power system; c. installing a warning system thatincludes a numerical display, a multicolor display and a plurality ofaudio sound devices in a driver compartment of said vehicles; connectinga warning system through a first input terminal and through a seriesconnected voltage device to said existing electrical wiring and powersystem for receiving electrical power; said warning system beingremotely disposed from said electronic microprocessor; and connecting anoutput of said warning system to the vehicle chassis for electricalgrounding; and d. connecting a plurality of input terminals of saidwarning system to said existing electrical wiring and power systemthrough a series connected interface circuit, for receiving digitallogic signals from said existing electrical wiring and power system foractivating a three-digit seven segment device to produce a numericaldisplay; and for activating an array of light emitting diodes to producemulticolor display; and for activating said plurality of audio sounddevices to generate multiple warning sounds and messages in said drivercompartment of said vehicles.
 11. A method of claim 10, wherein saidelectronic microprocessor components operate as digital logic circuits.12. A method of claim 10, wherein a single returned echo signal isgenerated after receipt of each 5 echo sound-waves and is inputted tosaid distance ranging circuit.
 13. A collision avoidance detection andwarning system adaptable for retro-fit to vehicles having an existingelectrical wiring and power system and utilizing the chassis of thevehicle as an electrical ground, comprising:a. an oscillator circuitwith an input terminal connected to a positive voltage carrying wire ofsaid existing electrical wiring and power system, and a first outputterminal connected to said chassis and three output terminals forgenerating oscillatory frequency signals; b. a distance ranging circuithaving two input terminals and five output terminals, a first inputterminal being connected to an output terminal of said oscillatorcircuit to receive an oscillatory frequency signal and generating a highvoltage low frequency clock and a plurality of high frequency triggerand reference output signals that are outputted from a first and secondoutput terminal, respectively; a third output terminal is connected tosaid chassis for electrical grounding; c. a plurality ofmulti-functional acoustical devices, having first and second inputterminals each operates first as a transmitter of sound waves during anon-time and then as a receiver of echo signals during an off-time; saiddevices being connected to said distance ranging circuit at said firstinput terminal for receiving said clock output signals therefrom and atsaid devices second input terminal for receiving said trigger andreference output signals therefrom and activating said devices asacoustical sound wave transmitter during said on-time and as a receiverof returned echo signals during said off-time; said plurality ofmulti-functional acoustical devices being connected at a first outputterminal of said acoustical devices to a second input terminal of saiddistance ranging circuit for inputting returned echo signals thereto,said distance ranging circuit converts said returned echo signals fromsaid acoustical devices into digital logic echo signals that are one oftwo output signals from said distance ranging circuit having atime-to-distance relationship with said trigger and reference outputsignal which define a time interval that it takes for a transmittedacoustical sound wave pulse to produce a returned echo pulse from aremote exterior object; d. a digital logic processing circuit having afirst input terminal connected to an output terminal of said oscillatorcircuit for receiving an oscillatory frequency output signal, a secondinput terminal connected to a fifth output terminal of said distanceranging circuit for receiving a plurality of said digital logic triggersignals; a third input connected to a fourth output terminal of saiddistance ranging circuit for receiving a plurality of digital logic echosignals; said digital logic trigger and said digital logic echo signalsare processed within said digital logic processing circuit to produce aplurality of output signals that equal a measure of the time-to-distancerelationship between a transmitted sound wave and a received returnedecho sound wave that are fed to a first drive circuit within saiddigital logic processing circuit to produce a plurality of binary codeddigital output signals which also equal a measure of thetime-to-distance relationship between a transmitted sound wave and areceived returned echo sound wave, that are fed to a series connectedcoded decimal-to-seven segment conversion circuit and a second drivecircuit within said digital logic processing circuit to produce aplurality of logic output signals; and e. a plurality of seven-segmentlight emitting diode devices of said detection and warning systemconnected to said first and second drive circuits of said digital logicprocessing circuit to receive output signals therefrom, for producingnumerical displays of the distances of objects detected by each of saidmulti-functional acoustical devices.
 14. A collision avoidance detectionand warning system having an oscillator circuit, a distance rangingcircuit and a plurality of multi-functional acoustical devices of claim13, which further includes:a. a voltage comparator processing circuithaving a first input terminal connected to an output terminal of saidoscillator circuit for receiving an oscillator frequency output signal;a second input terminal connected to said fifth output terminal of saiddistance ranging circuit for receiving a plurality of said digital logictrigger signals; a third input terminal connected to said fourth outputterminal of said distance ranging circuit for receiving a plurality ofdigital logic echo signals; said digital logic trigger and echo signalsare processed within said voltage comparator circuit to produce aplurality of voltage signals having levels which correspond to voltageranges that equal a time-to-distance relationship between a transmittedsound wave and a received returned echo sound wave; said plurality ofvoltage signals are inputed to three internal voltage comparatorscircuits, each of said voltage comparator circuits are set to generateoutput signals in preset voltage ranges, respectively, when a voltagesignal within said preset voltage ranges is inputed to a priorityencoder circuit, for generating output signals which correspond tovoltages within said preset ranges of said voltage comparators, that areutilized to activate an array of light emitting diodes used toilluminate a multicolor display and audio sound devices; b. saidmulticolor display device having circuitry and an array of lightemitting diodes in combination connected to said voltage comparatorprocessing circuit for receiving encoded signals therefrom to produce anilluminated display in three distinct colors when said array isactivated by said encoded signals; c. said circuit and audio sounddevices in combination connected to said voltage comparator processingcircuit for receiving signals therefrom for producing multiple distinctwarning sounds or messages corresponding to different ranges ofdistances of objects detected by said multi-functional acousticaldevices.
 15. A collision avoidance detection and warning system of claim14, in which said multicolor device produces a display of green, yellowand red, each corresponding to three distinct ranges of distances ofobjects exterior to the perimeter of said vehicle detected by saidmulti-functional acoustical devices.
 16. A collision avoidance detectionand warning system of claim 13, in which said plurality of transmittedsound waves consist of a plurality of a group of pulses, each group ofpulses being separated by a predetermined time interval, said grouped ofpulses define an on-time for said transmitters and said time intervalsbetween said grouped pulses defines an off-time for said transmitters.17. A collision avoidance detection and warning system of claim 13, inwhich in said off-time, said acoustical devices receive a plurality ofreturned echo analog sound wave signals that are converted by saiddistance ranging circuit to a plurality of digital logic echo signals.